loop-invariant.c (get_inv_cost): Handle register class.

ChangeLog:
2014-06-30  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

	* loop-invariant.c (get_inv_cost): Handle register class.
	(gain_for_invariant): Check the register pressure of the inv
	and its overlapped register class, other than all.

testsuite/ChangeLog:
2014-06-30  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

	* ira-loop-pressure.c: New test.

From-SVN: r212135

4 files changed, 76 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 14f6769..4cc167a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-30  Zhenqiang Chen  <zhenqiang.chen@linaro.org>
+
+	* loop-invariant.c (get_inv_cost): Handle register class.
+	(gain_for_invariant): Check the register pressure of the inv
+	and its overlapped register class, other than all.
+
 2014-06-30  Gerald Pfeifer  <gerald@pfeifer.com>
 
 	* doc/invoke.texi (Optimize Options): Fix descriptions of
diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index 3852c6b..d47d461 100644
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -1087,16 +1087,22 @@ get_pressure_class_and_nregs (rtx insn, int *nregs)
 }
 
 /* Calculates cost and number of registers needed for moving invariant INV
-   out of the loop and stores them to *COST and *REGS_NEEDED.  */
+   out of the loop and stores them to *COST and *REGS_NEEDED.  *CL will be
+   the REG_CLASS of INV.  Return
+     -1: if INV is invalid.
+      0: if INV and its depends_on have same reg_class
+      1: if INV and its depends_on have different reg_classes.  */
 
-static void
-get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
+static int
+get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed,
+	      enum reg_class *cl)
 {
   int i, acomp_cost;
   unsigned aregs_needed[N_REG_CLASSES];
   unsigned depno;
   struct invariant *dep;
   bitmap_iterator bi;
+  int ret = 1;
 
   /* Find the representative of the class of the equivalent invariants.  */
   inv = invariants[inv->eqto];
@@ -1112,7 +1118,7 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
 
   if (inv->move
       || inv->stamp == actual_stamp)
-    return;
+    return -1;
   inv->stamp = actual_stamp;
 
   if (! flag_ira_loop_pressure)
@@ -1124,6 +1130,8 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
 
       pressure_class = get_pressure_class_and_nregs (inv->insn, &nregs);
       regs_needed[pressure_class] += nregs;
+      *cl = pressure_class;
+      ret = 0;
     }
 
   if (!inv->cheap_address
@@ -1164,6 +1172,8 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
   EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi)
     {
       bool check_p;
+      enum reg_class dep_cl = ALL_REGS;
+      int dep_ret;
 
       dep = invariants[depno];
 
@@ -1171,7 +1181,7 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
       if (dep->move)
 	continue;
 
-      get_inv_cost (dep, &acomp_cost, aregs_needed);
+      dep_ret = get_inv_cost (dep, &acomp_cost, aregs_needed, &dep_cl);
 
       if (! flag_ira_loop_pressure)
 	check_p = aregs_needed[0] != 0;
@@ -1181,6 +1191,12 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
 	    if (aregs_needed[ira_pressure_classes[i]] != 0)
 	      break;
 	  check_p = i < ira_pressure_classes_num;
+
+	  if ((dep_ret == 1) || ((dep_ret == 0) && (*cl != dep_cl)))
+	    {
+	      *cl = ALL_REGS;
+	      ret = 1;
+	    }
 	}
       if (check_p
 	  /* We need to check always_executed, since if the original value of
@@ -1214,6 +1230,7 @@ get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
 	}
       (*comp_cost) += acomp_cost;
     }
+  return ret;
 }
 
 /* Calculates gain for eliminating invariant INV.  REGS_USED is the number
@@ -1228,10 +1245,12 @@ gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
 		    bool speed, bool call_p)
 {
   int comp_cost, size_cost;
+  enum reg_class cl;
+  int ret;
 
   actual_stamp++;
 
-  get_inv_cost (inv, &comp_cost, regs_needed);
+  ret = get_inv_cost (inv, &comp_cost, regs_needed, &cl);
 
   if (! flag_ira_loop_pressure)
     {
@@ -1240,6 +1259,11 @@ gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
 		   - estimate_reg_pressure_cost (new_regs[0],
 						 regs_used, speed, call_p));
     }
+  else if (ret < 0)
+    return -1;
+  else if ((ret == 0) && (cl == NO_REGS))
+    /* Hoist it anyway since it does not impact register pressure.  */
+    return 1;
   else
     {
       int i;
@@ -1248,6 +1272,10 @@ gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
       for (i = 0; i < ira_pressure_classes_num; i++)
 	{
 	  pressure_class = ira_pressure_classes[i];
+
+	  if (!reg_classes_intersect_p (pressure_class, cl))
+	    continue;
+
 	  if ((int) new_regs[pressure_class]
 	      + (int) regs_needed[pressure_class]
 	      + LOOP_DATA (curr_loop)->max_reg_pressure[pressure_class]
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 86276d9..5a9d73a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-06-30  Zhenqiang Chen  <zhenqiang.chen@linaro.org>
+
+	* ira-loop-pressure.c: New test.
+
 2014-06-29  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
 	PR fortran/36275
diff --git a/gcc/testsuite/gcc.dg/ira-loop-pressure.c b/gcc/testsuite/gcc.dg/ira-loop-pressure.c
new file mode 100644
index 0000000..7ef4fa7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ira-loop-pressure.c
@@ -0,0 +1,32 @@
+/* Loop2_invariants pass should distinguish register pressures of different
+   register classes.  In this case, register pressue of INT is high.  But
+   we can still move the FP invariant out of the loop.  */
+
+/* { dg-do compile { target { x86_64-*-* && lp64 } } } */
+/* { dg-options "-O2 -fira-loop-pressure -fdump-rtl-loop2_invariant " } */
+
+float tt;
+extern void foo2 (int *, int *, int *, int *, int *, int *);
+extern int foo3 (int, int, int, int, int, int);
+int foo (int a, int b, int c, int d)
+{
+   int i = a;
+   int t1, t2, t3, t4, t5, t6;
+   t1 = t2 = t3 = t4 = t5 = t6 = 0;
+
+   for (; i > 0; i += c)
+    {
+      tt += 123456.0;
+      if (d > t1 + t2)
+	tt = 3.0;
+      foo2 (&t1, &t2, &t3, &t4, &t5, &t6);
+      t1 += t3 + t4 + a + b;
+      t2 -= t5 - t6 - c - d;
+    }
+
+ return foo3 (t1, t2, t3, t4, t5, t6);
+}
+
+/* { dg-final { scan-rtl-dump "Decided to move invariant" "loop2_invariant"  } } */
+/* { dg-final { cleanup-rtl-dump "loop2_invariant" } } */
+